The invention relates to an exhaust system for an internal combustion automotive engine, such as V-engine or a boxer engine. Typical high performance internal combustion automotive engines have a left group of cylinders and a right group of cylinders, each of which is connectable to an individual left or right exhaust tract. In such an exhaust system each exhaust tract, the left exhaust tract and the right exhaust tract, comprises a tract structure which defines a tract inlet into which the exhaust gas is injected from the respective left or right group of cylinders and one or more exhaust outlets opening into the atmosphere for releasing exhaust gas from the exhaust system.
Each exhaust tract of such an exhaust system can run from its group of cylinders towards its exhaust outlet without any connection to the other tract. In such a setup the exhaust gas from a left group of cylinders is transported exclusively through the left exhaust tract and exclusively to a left exhaust opening. At the same time, exhaust gas from the right group of cylinders is transported through the right exhaust tract towards the right exhaust outlet, exclusively. No exhaust gas from one tract is in such a system delivered into the other tract. However, for improving performance and in order to be able to improve control over the system's sound emission, known exhaust systems have been provided with one or more exhaust transmission pipes which connect the left exhaust tract to the right exhaust tract. The exhaust gas transmission pipes are arranged in exhaust systems such that they connect the left exhaust tract to the right exhaust tract in an H-shaped manner and can be provided with a valve in order to be able to open and/or close the exhaust gas transmission through the exhaust gas transmission pipe.
A typical design for such an exhaust outlet is known from U.S. Pat. No. 7,703,574 B2 in which the left exhaust tract is connected to the right exhaust tract with two transmission pipes so that two H-shaped transmissions are realized, one of which is arranged relatively close to the engine and the other one of which is arranged closer to the exhaust openings.
Known exhaust systems allow for some control over the exhaust system's acoustics and may improve performance in specific operating states of the engine. However, particularly at high engine operating parameters, they suffer from significant disadvantages with respect to both sound emission and performance. At high engine operation parameters, the above-mentioned exhaust systems emit a disturbing streaming noise. Furthermore, the the transmission pipe induces turbulences into the exhaust gas streams in both the left and the right exhaust tract which limit the performance of the engine and muffling devices. The performance gain is particularly limited by the amount of exhaust gas which may be transferred from one line to the other line being smaller than desired.